In the semiconductor industry, the creation of high-purity, but above all also defect-free layers is of great importance for the production of semiconductor components. Defects, particularly crystal defects, have a decisive influence on the functionality and durability of semiconductor components. Very many semiconductor components are manufactured directly on monocrystalline substrates, which have an extremely high purity and relatively low defect density. Semiconductor substrates of such a type are produced using special processes, particularly the Czochralski process. For the most part, methods of this type create a very large single crystal, which is sawn or cut in further process steps to give the individual substrates.
Very often it is necessary to create further monocrystalline layers with a correspondingly low defect structure directly on surfaces which are already present. These monocrystalline layers may be created by different processes. In order to create high-purity and above all defect-free layers, use is very often made of the lateral overgrowth method.
In order to obtain relatively defect-free monocrystalline layers, in a first process step, a mask is created on a seed layer surface. The mask covers the majority of the seed layer surface. At well-defined locations, the mask has mask openings, via which the parts of the surface are exposed. In the prior art, the mask is predominantly produced using photolithographic methods.
For the most part, masks are produced by means of photolithographic processes with a plurality of process steps. A photoresist must be applied in a first process step. The photoresist is then exposed, developed and etched. In very many cases, it is not possible to use simple polymer-based photoresists, as the masks must be comprised of a hard material layer. Material deposition and above all the etching processes consequently become more difficult, more complicated and more expensive.